When sock_wait_state() returns -EINPROGRESS, "sk->sk_state" is LLCP_CONNECTING. In this case, llcp_sock_connect() is repeatedly invoked, nfc_llcp_sock_link() will add sk to local->connecting_sockets twice. sk->sk_node->next will point to itself, that will make an endless loop and hang-up the system. To fix it, check whether sk->sk_state is LLCP_CONNECTING in llcp_sock_connect() to avoid repeated invoking.
Fixes: b4011239a08e ("NFC: llcp: Fix non blocking sockets connections") Reported-by: "kiyin(尹亮)" kiyin@tencent.com Link: https://www.openwall.com/lists/oss-security/2020/11/01/1 Cc: stable@vger.kernel.org #v3.11 Signed-off-by: Xiaoming Ni nixiaoming@huawei.com --- net/nfc/llcp_sock.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c index 59172614b249..a3b46f888803 100644 --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -673,6 +673,10 @@ static int llcp_sock_connect(struct socket *sock, struct sockaddr *_addr, ret = -EISCONN; goto error; } + if (sk->sk_state == LLCP_CONNECTING) { + ret = -EINPROGRESS; + goto error; + }
dev = nfc_get_device(addr->dev_idx); if (dev == NULL) {